Reciprocal Increased Risk of Parkinson's, Prostate Cancer

(HealthDay News) – Patients with Parkinson's disease (PD) have a significantly increased risk of prostate cancer and melanoma, which extends to their third-degree relatives, and there is evidence of a reciprocal risk, according to a study published online Sept 3 in the Archives of Neurology.

To estimate the relative risk of cancer in individuals with PD and their first-, second-, and third-degree relatives, Seth A Kareus, MD, from the University of Utah in Salt Lake City, and colleagues used a computerized genealogy for approximately 2.3 million Utah pioneers and their descendants. The genealogic resource was linked to a statewide cancer registry (including data on 100,817 individuals) and statewide death certificates with 2,998 individuals with PD listed as a cause of death from 1904–2008.

The researchers found that the only cancers observed in significant excess among PD cases were melanoma and prostate cancer. Colorectal, lung, pancreas, and stomach cancers were observed at lower than expected rates. Among the PD population, as well as among their relatives, there was a significantly increased risk for prostate cancer. In 22,147 prostate cancer cases and their relatives there was a reciprocal significantly increased risk for PD. The risk for melanoma was found to be significantly elevated in the Utah PD population as well as in their relatives. In the 7,841 Utah melanoma cases and their relatives there was a reciprocal significantly increased relative risk for PD.

"These data argue strongly for a significant shared genetic risk for specific cancers on the one hand and neurodegeneration on the other," the authors write.